Remove applyPageScaleFactorinCompositor in settings.in

Based on the code search https://code.google.com/p/chromium/codesearch#search/&q=applyPageScaleFactorInCompositor&sq=package:chromium&type=cs. and reference to http://code.google.com/p/chromium/issues/detail?id=229230
we don't use this setting. Cleaning the code.

BUG=290629

Review URL: https://codereview.chromium.org/122193002

git-svn-id: svn://svn.chromium.org/blink/trunk@164373 bbb929c8-8fbe-4397-9dbb-9b2b20218538